Phys. Rev. B 110, 104420 (2024) – Published 13 September 2024
Stoner magnetism in bands with Berry curvature features a coupling between spin chirality density and Berry’s orbital magnetism, arising without microscopic spin-orbital interactions. Carriers moving in a spin texture perceive it as a geometric magnetic field coupled to their orbital motion through a spin-dependent gauge field. This emergent spin-orbital interaction, previously predicted to enable chiral magnons at system boundaries, also favors chiral spin textures such as skyrmions – topologically protected, particle-like objects stabilized in the ground state.
M. Hild, E. Mönch, L. E. Golub, I. A. Dmitriev, I. Yahniuk, K. Amann, J. Amann, J. Eroms, J. Wunderlich, D. Weiss, C. Consejo, C. Bray, K. Maussang, F. Teppe, J. Gumenjuk-Sichevska, K. Watanabe, T. Taniguchi, and S. D. Ganichev
Phys. Rev. B 110, 125303 (2024) – Published 13 September 2024
Here, the authors study the ratchet effect – the conversion of alternating fields in the terahertz and gigahertz range into direct current – using a 2D metamaterial formed by monolayer graphene and a nearby gate with an array of triangular holes. A combined experimental and theoretical study shows that application of magnetic field leads to giant enhancement of the ratchet current and emergence of quantum magneto-oscillations, also featuring a complex Fano shape of the cyclotron resonance and well-pronounced electron spin resonance.
